Field of the Invention
The present invention relates to a tire curing mold in which a plurality of vent holes are provided in a side forming surface coming into contact with a side wall portion of a tire, and a method of manufacturing a tire using the tire curing mold.
Description of the Related Art
Conventionally, in a tire curing mold which is used for curing a pneumatic tire, a plurality of vent holes are provided in a side forming surface which comes into contact with a side wall portion of the tire (refer, for example, to Patent Documents 1 and 2). With the structure mentioned above, extra air between the tire and the side forming surface is discharged outside the mold. As a result, it is possible to prevent generation of air accumulation causing a rubber fracture which is called as lightness or bare, and it is possible to achieve formation of a good tire appearance.
On the other hand, there has been known a pneumatic tire in which a projection portion is provided on a surface of a side wall portion. The projection portion constitutes, for example, a display of letters, numerical characters and figures for enhancing a design property and a decorative property, or constitutes a rib for improving a traveling property and an external damage resistance on a bad road such as a rocky area. In this case, a recess portion corresponding to the projection portion is provided on the side forming surface of the tire curing mold.
However, since the recess portion mentioned above is deeper than a profile of the side forming surface, it takes a long time to fill the recess portion with a required amount of rubber at the curing time, and a rubber flow within the recess portion tends to be lowered. As a result, the air accumulation tends to be generated within the recess portion, and there is a concern that the appearance of the tire is deteriorated by the rubber fracture of the projection portion caused by the air accumulation.